Grimm, also known as the Nightmare King, is a supporting antagonist in Hollow Knight, serving as the titular main antagonist of "The Grimm Troupe" DLC. He is the villainous leader of the mysterious Grimm Troupe, a group of performers who seek to collect the flames of the fallen kingdom of Hallownest in order to prolong the Nightmare's Heart, a process the Troupe calls "The Ritual", and manipulates the Knight into doing his bidding.

Grimm is the master of Grimm's Troupe, a mysterious traveling circus. In reality, Grimm and his Troupe travel from the Nightmare Realm to wherever the Lantern has been lit by his followers. They collect Flames from ruined realms to fuel the sinister being that enslaves the Troupe, the Nightmare Heart. The Company Master has a charming and playful personality. However, being the Nightmare King , his thoughts are focused on being a slave or vessel to the Heart. His ritual to feed the Heart consists of first growing the Child of Grimm with Nightmare Flames. Then, killing the Nightmare King so that he is reborn through the Child. You can be all the caracter you want. Have fun

The Knight is a discarded Vessel. He is the child of the Pale King and the White Lady, born in the abyss with Void inside their shell. Hornet is the Knight's half-sister through their shared father. Like the rest of their Vessel siblings, the Knight is genderless. After climbing out of their birthplace in the Abyss, the Knight witnessed their sibling The Hollow Knight, being taken out of the Abyss by the Pale King. The entrance to the Abyss was sealed, causing the Knight to fall back down. Sometime after this, despite the entrance being sealed, the Knight and some of their siblings managed to escape the Abyss. (You can be any character u want, you found the Knight resting in the bank on dirtmouth)